Question: Kubernetes ingress controller

Question: Ingress controller implements Ingress resources, routing external HTTP/HTTPS to services. Popular controllers: nginx-ingress, Traefik, HAProxy. Ingress resource defines rules: host (foo.com), paths (/api -> api-service, / -> frontend). Annotations configure TLS, rate limiting, auth. Install controller first, then create Ingress resources.

Question: kubernetes overview ingress controller

Question: k8s ingress nginx traefik

Question: ingress rules path host

Question: what is a kubernetes ingress controller and how does it route external traffic to services

Question: how do you configure ingress rules for path-based and host-based routing in kubernetes


Question: docker layer caching

Question: Docker caches each instruction as a layer. Cache invalidates when instruction or context changes, invalidating all subsequent layers. Optimization: order from least to most frequently changing. Copy package.json and install deps before copying source code. Use .dockerignore. Multi-stage builds discard intermediate layers. COPY --from for selective extraction.

Question: docker overview layer caching build

Question: dockerfile cache optimization

Question: docker build cache layers

Question: how does docker layer caching work and how do you optimize dockerfiles for faster builds

Question: what dockerfile practices maximize cache hits when building docker images


Question: ssh tunnel port forwarding

Question: Local forwarding (-L): access remote service through local port. ssh -L 8080:localhost:3000 server—localhost:8080 reaches server's port 3000. Remote forwarding (-R): expose local service through remote port. ssh -R 8080:localhost:3000 server—server:8080 reaches your port 3000. Use for accessing databases behind firewalls, exposing dev servers temporarily.

Question: ssh overview tunnel port forwarding

Question: ssh local remote forward

Question: ssh -L -R tunnel

Question: how to set up ssh tunnels for local and remote port forwarding

Question: what is the difference between ssh local port forwarding and remote port forwarding


Question: rest api pagination

Question: Offset pagination: ?page=2&limit=20 or ?offset=20&limit=20. Simple but slow for deep pages, inconsistent with real-time inserts. Cursor pagination: ?cursor=abc123&limit=20, cursor encodes position. Consistent, efficient, better for infinite scroll. Return next_cursor in response. Use Link headers or response body for pagination URLs.

Question: rest overview api pagination

Question: api pagination offset cursor

Question: paginated response next page

Question: what are the different approaches to implementing pagination in rest apis

Question: how do offset-based and cursor-based pagination compare for api design


Question: solid principles explained

Question: SOLID: Single Responsibility (one reason to change), Open/Closed (open for extension, closed for modification), Liskov Substitution (subtypes substitutable for base types), Interface Segregation (many specific interfaces over one general), Dependency Inversion (depend on abstractions not concretions). Following SOLID produces loosely coupled, testable, maintainable code.

Question: solid principles oop

Question: single responsibility open closed

Question: solid design principles

Question: what are the solid principles in object oriented design

Question: how do the solid principles improve code maintainability and flexibility


Question: protobuf vs json

Question: JSON: human-readable, self-describing, universal support, larger payload. Protobuf: binary format, 3-10x smaller, faster serialization, requires schema (.proto files), strong typing. Use JSON for public APIs, debugging, human interaction. Use Protobuf for internal microservices, high-throughput systems, gRPC. Schema evolution with field numbers enables backward compatibility.

Question: protobuf json comparison

Question: protocol buffers serialization

Question: grpc protobuf format

Question: what are the differences between protocol buffers and json for data serialization

Question: when should you use protobuf instead of json for api communication


Question: linux namespaces containers

Question: Containers use Linux namespaces for isolation: PID (process tree), NET (network stack), MNT (filesystem mounts), UTS (hostname), IPC (inter-process communication), USER (user IDs). Cgroups limit resource usage (CPU, memory). Together they isolate processes without full VM overhead. Containers share host kernel but see isolated views of system resources.

Question: linux overview namespaces containers

Question: container isolation namespace cgroup

Question: docker linux namespaces

Question: how do linux namespaces enable container isolation

Question: what kernel features do docker and containers use for process isolation


Question: GraphQL subscriptions websocket

Question: GraphQL subscriptions enable real-time updates via persistent connections. Client subscribes: subscription { messageAdded { text } }. Server pushes when events occur. Typically uses WebSocket with graphql-ws protocol. Server maintains subscription registry, publishes events through PubSub. Apollo Server and Relay support subscriptions natively.

Question: graphql overview subscriptions websocket

Question: graphql realtime subscriptions

Question: graphql subscription server

Question: how do graphql subscriptions work for real-time data updates

Question: what is the underlying protocol for graphql subscriptions and how do you implement them


Question: stateless vs stateful services

Question: Stateless services don't store client state between requests—any instance can handle any request. Scale by adding instances, no session affinity needed. Stateful services maintain client state, requiring sticky sessions or shared storage. Make services stateless by storing session in JWT tokens, Redis, or databases. Stateless is preferred for horizontal scaling and resilience.

Question: stateless stateful service

Question: stateless api design

Question: session state storage

Question: what is the difference between stateless and stateful services in application architecture

Question: why are stateless services easier to scale and how do you handle state when needed


Question: git bisect debugging

Question: git bisect does binary search through commits to find where bug was introduced. Start: git bisect start, git bisect bad (current has bug), git bisect good v1.0 (known good commit). Git checks out middle commit—test and mark git bisect good or git bisect bad. Repeat until found. Automate with git bisect run ./test.sh. End with git bisect reset.

Question: git bisect bug finding

Question: git bisect good bad

Question: binary search git commit

Question: how to use git bisect to find the commit that introduced a bug

Question: what is the git bisect workflow for binary search debugging through commit history


Question: dns propagation time

Question: DNS propagation is time for changes to spread through cached resolvers worldwide. TTL (Time To Live) controls cache duration. High TTL (86400s) means up to 24h wait. Before changes, lower TTL to 300s, wait for old TTL, make change, then restore TTL. Use dig @8.8.8.8 domain.com to check Google's view. Full propagation can take 24-48h for high-TTL records.

Question: dns overview propagation time

Question: dns ttl propagation delay

Question: dns changes not working

Question: why do dns changes take time to propagate and how can you speed it up

Question: what is dns propagation and how does ttl affect how quickly changes are visible


Question: fall of the Roman Empire

Question: The Western Roman Empire fell in 476 AD when Odoacer deposed Romulus Augustulus. Contributing factors included economic troubles, military overextension, political instability with rapid emperor turnover, pressure from Germanic tribes, and the division of the empire. The Eastern Roman Empire (Byzantine) survived until 1453.

Question: roman empire fall causes

Question: decline of rome 476 AD

Question: western roman empire collapse

Question: what were the main causes of the fall of the western roman empire

Question: how did economic, military, and political factors contribute to rome's collapse


Question: causes of World War I

Question: WWI was caused by MAIN: Militarism, Alliances, Imperialism, Nationalism. The assassination of Archduke Franz Ferdinand on June 28, 1914 in Sarajevo triggered a chain reaction through alliance systems. Austria-Hungary declared war on Serbia, pulling in Russia, Germany, France, and Britain within weeks.

Question: world war 1 causes

Question: ww1 assassination archduke franz ferdinand

Question: causes great war 1914

Question: what were the main causes and triggers of world war one

Question: how did the assassination of archduke franz ferdinand lead to a global war


Question: ancient Egypt pyramids construction

Question: The pyramids were built using ramps, levers, and organized labor forces of tens of thousands of workers. Limestone blocks weighing 2.5 tons average were quarried nearby and transported on sledges. Workers were not slaves but paid laborers housed in nearby villages. The Great Pyramid took approximately 20 years to complete around 2560 BC.

Question: egyptian pyramids how built

Question: pyramid construction ancient egypt

Question: great pyramid giza building

Question: how were the ancient egyptian pyramids constructed without modern technology

Question: what techniques and labor did ancient egyptians use to build the pyramids at giza


Question: French Revolution timeline

Question: 1789: Estates-General convenes, Bastille stormed July 14. 1791: Constitutional monarchy established. 1792: Republic declared, king executed. 1793-94: Reign of Terror under Robespierre, 17,000 guillotined. 1794: Thermidorian Reaction ends Terror. 1799: Napoleon's coup establishes Consulate.

Question: french overview revolution timeline events

Question: french revolution 1789 bastille

Question: reign of terror robespierre

Question: what were the major events of the french revolution in chronological order

Question: how did the french revolution progress from the storming of the bastille to napoleon


Question: Ottoman Empire history

Question: Founded by Osman I around 1299, the Ottoman Empire conquered Constantinople in 1453, ending the Byzantine Empire. At its peak under Suleiman the Magnificent (1520-1566), it controlled Southeast Europe, Western Asia, and North Africa. Gradual decline through the 18th-19th centuries culminated in dissolution after WWI in 1922.

Question: ottoman overview empire history

Question: ottoman sultanate 1299 1922

Question: turkish ottoman empire rise fall

Question: what was the history of the ottoman empire from its founding to its dissolution

Question: how did the ottoman empire rise to become a major world power and eventually decline


Question: American Civil War battles

Question: Major battles: Fort Sumter (1861, war begins), Bull Run (Confederate victory), Antietam (1862, bloodiest single day, led to Emancipation Proclamation), Gettysburg (1863, Union turning point), Vicksburg (Union controls Mississippi), Sherman's March (1864), Appomattox (1865, Lee surrenders). Total casualties exceeded 600,000.

Question: american overview civil war battles

Question: civil war gettysburg antietam

Question: union confederate battles 1861

Question: what were the major battles of the american civil war

Question: which battles were turning points in the civil war between union and confederate forces


Question: Ming Dynasty China

Question: The Ming Dynasty (1368-1644) was founded by Zhu Yuanzhang after overthrowing Mongol Yuan rule. Notable achievements: construction of the Forbidden City, voyages of Zheng He, restoration of the Great Wall, and flourishing arts and porcelain. Fell to the Manchu Qing after peasant rebellions weakened central authority.

Question: ming overview dynasty china history

Question: ming dynasty 1368 1644

Question: chinese ming emperors

Question: what were the major achievements and characteristics of the ming dynasty in china

Question: how did the ming dynasty rise to power and what led to its eventual fall


Question: Viking Age exploration

Question: The Viking Age (793-1066 AD) saw Norse expansion across Europe and beyond. Vikings raided British Isles and France, settled Iceland (874), Greenland (985), and reached North America (Vinland, c.1000) under Leif Erikson. They also traveled east through Russia to Constantinople and served as Varangian Guard.

Question: viking overview age exploration

Question: vikings norse exploration america

Question: viking raids settlements

Question: where did the vikings explore and settle during the viking age

Question: what routes did norse explorers take and what lands did they discover


Question: Industrial Revolution inventions

Question: Key inventions: Spinning Jenny (1764), Water Frame (1769), Steam Engine improved by James Watt (1769), Power Loom (1785), Cotton Gin (1793), Steam Locomotive (1804). These enabled factory production, mass manufacturing, and transformed society from agricultural to industrial. Britain led the revolution starting around 1760.

Question: industrial overview revolution inventions

Question: industrial revolution steam engine

Question: 18th century industrial innovations

Question: what were the key inventions that drove the industrial revolution

Question: how did the steam engine and textile machinery transform manufacturing in the 18th century


Question: Byzantine Empire Constantinople

Question: The Byzantine Empire was the continuation of the Eastern Roman Empire, lasting from 330 AD (Constantinople founded) to 1453. At its peak under Justinian I, it reconquered much of the western Mediterranean. Constantinople was the largest and wealthiest European city for centuries until falling to Ottoman Turks under Mehmed II on May 29, 1453.

Question: byzantine overview empire constantinople

Question: eastern roman empire byzantium

Question: fall of constantinople 1453

Question: what was the byzantine empire and how long did it last after rome fell

Question: how did constantinople serve as the capital of the byzantine empire until 1453


Question: Aztec Empire civilization

Question: The Aztec Empire (1428-1521) dominated central Mexico from their capital Tenochtitlan, built on an island in Lake Texcoco (modern Mexico City). Population reached 200,000+. Known for pyramids, human sacrifice, chinampas (floating gardens), and tribute system. Conquered by Hernán Cortés in 1521 with help from rival indigenous groups and smallpox.

Question: aztec overview empire civilization

Question: aztec tenochtitlan mexico

Question: aztec history mesoamerica

Question: what was the aztec empire and how did their civilization develop in mesoamerica

Question: how did the aztecs build tenochtitlan and what led to the fall of their empire


Question: Renaissance Italy Florence

Question: The Renaissance began in Florence around 1400 due to wealth from banking and trade, political stability, and classical heritage. The Medici family, especially Lorenzo the Magnificent, patronized artists like Leonardo, Michelangelo, and Botticelli. Florence's guilds, humanism from rediscovered Greek texts, and competition among city-states drove cultural innovation.

Question: renaissance overview italy florence

Question: italian renaissance medici

Question: florence renaissance art

Question: why did the renaissance begin in italy particularly in florence

Question: how did the medici family and florence become the center of the italian renaissance


Question: Cold War Berlin Wall

Question: The Berlin Wall was built overnight on August 13, 1961 by East Germany to stop emigration to the West—3.5 million had fled since 1945. It divided Berlin for 28 years, symbolizing the Iron Curtain. Fell November 9, 1989 after Hungary opened its border and East German protests grew. Germany reunified October 3, 1990.

Question: cold overview war berlin wall

Question: berlin wall 1961 1989

Question: east west germany division

Question: what was the significance of the berlin wall during the cold war

Question: why was the berlin wall built and what led to its fall in 1989


Question: Mongol Empire Genghis Khan

Question: Genghis Khan united Mongol tribes by 1206 and conquered from Korea to Poland by his death in 1227. The empire peaked under his grandsons, spanning 24 million km²—largest contiguous empire ever. Success came from cavalry tactics, meritocracy, religious tolerance, and the Yam relay system. Divided into khanates after 1260.

Question: mongol overview empire genghis khan

Question: mongol conquests 13th century

Question: genghis khan mongol history

Question: how did genghis khan build the mongol empire into the largest contiguous land empire

Question: what territories did the mongol empire conquer and how did they administer such vast lands


Question: ancient Greece democracy Athens

Question: Athenian democracy emerged under Cleisthenes (508 BC) and peaked under Pericles (461-429 BC). Citizens (adult male non-slaves) voted directly in the Assembly (Ekklesia) on laws and policy. The Council of 500, chosen by lot, set the agenda. Jury courts had hundreds of jurors. About 30,000 of 300,000 residents were citizens.

Question: ancient overview greece democracy athens

Question: athenian democracy 5th century bc

Question: greek democracy origins

Question: how did democracy develop in ancient athens and how did it function

Question: what were the key institutions and practices of athenian democracy


Question: Protestant Reformation Martin Luther

Question: Martin Luther posted his 95 Theses on October 31, 1517 in Wittenberg, criticizing indulgences and papal authority. Key ideas: salvation by faith alone, scripture as sole authority, priesthood of all believers. The printing press spread his ideas rapidly. Luther was excommunicated in 1521. The Reformation split Western Christianity and sparked religious wars across Europe.

Question: protestant reformation luther

Question: martin luther 95 theses

Question: reformation 1517 catholic church

Question: what started the protestant reformation and what were its main ideas

Question: how did martin luther's 95 theses challenge the catholic church and spread across europe


Question: Silk Road trade routes

Question: The Silk Road was a network of trade routes connecting China to the Mediterranean from around 130 BC to 1450s AD. Goods traded: silk, spices, porcelain from East; gold, glass, horses from West. Also spread Buddhism, Islam, technologies like paper and gunpowder, and unfortunately, the Black Death. Named by German geographer Ferdinand von Richthofen in 1877.

Question: silk road trade route

Question: silk road ancient trade china

Question: silk road history commerce

Question: what was the silk road and how did it connect east and west

Question: what goods and ideas were exchanged along the ancient silk road trade routes


Question: Napoleonic Wars Europe

Question: The Napoleonic Wars (1803-1815) saw France under Napoleon dominate continental Europe through brilliant campaigns at Austerlitz, Jena, and Wagram. His empire stretched from Spain to Poland. The failed 1812 Russian invasion (600,000 troops, 100,000 returned) began his decline. Exiled to Elba 1814, returned for Hundred Days, finally defeated at Waterloo June 18, 1815.

Question: napoleonic overview wars europe

Question: napoleon bonaparte campaigns

Question: napoleonic era 1803 1815

Question: what were the major campaigns and outcomes of the napoleonic wars

Question: how did napoleon's military conquests reshape europe and lead to his downfall


Question: ancient Mesopotamia civilizations

Question: Mesopotamia (modern Iraq) between Tigris and Euphrates rivers hosted the world's first civilizations. Sumerians (4500-1900 BC) invented writing (cuneiform), the wheel, sailboat, and plow. Akkadian Empire under Sargon was first empire. Babylon produced Hammurabi's Code. Assyrians and Persians followed. Agriculture surplus enabled cities, specialization, and complex society.

Question: ancient overview mesopotamia civilizations

Question: mesopotamia sumer babylon

Question: cradle of civilization tigris euphrates

Question: what civilizations arose in ancient mesopotamia and what were their achievements

Question: why is mesopotamia called the cradle of civilization and what did sumerians invent


Question: Meiji Restoration Japan

Question: The Meiji Restoration (1868) ended 250 years of Tokugawa shogunate rule, restoring imperial power under Emperor Meiji. Japan rapidly industrialized and westernized: abolished feudalism, created national army, built railways, established constitution (1889). Slogan: 'Rich country, strong army.' Japan defeated China (1895) and Russia (1905), becoming a world power within 50 years.

Question: meiji overview restoration japan

Question: meiji era modernization 1868

Question: japan meiji emperor reform

Question: what was the meiji restoration and how did it transform japan

Question: how did japan modernize so rapidly during the meiji period from 1868 to 1912


Question: Black Death plague Europe

Question: The Black Death (1347-1351) killed 75-200 million people, 30-60% of Europe's population. Caused by Yersinia pestis bacteria spread by fleas on rats, it arrived via Genoese ships from Crimea. Symptoms: buboes, fever, death within days. Consequences: labor shortages raised wages, weakened feudalism, sparked religious movements and persecution of Jews.

Question: black overview death plague europe

Question: bubonic plague 1347 medieval

Question: black death medieval europe

Question: what was the black death and how did it impact medieval europe

Question: how did the bubonic plague spread across europe and what were its consequences


Question: Spanish Conquest Americas

Question: Hernán Cortés conquered the Aztec Empire (1519-1521) with 500 soldiers, allying with Tlaxcalans and exploiting Montezuma's hesitation. Francisco Pizarro conquered the Inca Empire (1532-1533) capturing Atahualpa during civil war. Spanish advantages: steel weapons, horses, gunpowder, and crucially, Old World diseases like smallpox that killed 90% of indigenous populations.

Question: spanish overview conquest americas

Question: conquistadors cortez pizarro

Question: spanish colonization new world

Question: how did spanish conquistadors conquer the aztec and inca empires

Question: what factors enabled spain to colonize the americas so rapidly in the 16th century


Question: World War II D-Day

Question: D-Day, June 6, 1944, was the largest amphibious invasion in history. Operation Overlord landed 156,000 Allied troops on five Normandy beaches (Utah, Omaha, Gold, Juno, Sword). Despite 10,000+ casualties, it established a Western Front, leading to Paris liberation (August 1944) and Germany's surrender (May 1945). Supreme Commander: Dwight D. Eisenhower.

Question: world war 2 d-day normandy

Question: d-day june 6 1944 invasion

Question: operation overlord ww2

Question: what happened on d-day and why was the normandy invasion a turning point in world war two

Question: how was the d-day invasion of normandy planned and executed by allied forces


Question: Han Dynasty China achievements

Question: The Han Dynasty (206 BC - 220 AD) is considered China's golden age. Achievements: Silk Road trade established, paper invented (105 AD), civil service exams introduced, Confucianism became state ideology. Population reached 60 million. So influential that ethnic Chinese still call themselves 'Han people.' Collapsed due to court intrigue, eunuch power, and Yellow Turban Rebellion.

Question: han overview dynasty china achievements

Question: han dynasty 206 bc history

Question: ancient china han empire

Question: what were the major achievements and contributions of the han dynasty in china

Question: why is the han dynasty considered a golden age in chinese history