Easy Learn
A complete, beginner-to-production guide to multi-master replication (also called multi-primary or active-active replication): the classroom-whiteboard analogy for why one master can’t serve a global user base, the historical arc from 1960s mainframes through 1980s-90s primary-replica setups, 1990s Lotus Notes collaborative sync, and the 2000s explosion driven by Amazon, Google, and…
A ground-up tour of OAuth 2.0 — the delegated-authorization protocol behind “Sign in with Google,” Slack integrations, Open Banking, and every “connect this to that” flow on the modern internet. Covers the four roles (Resource Owner, Client, Authorization Server, Resource Server), the core artifacts (authorization code, access token, refresh token,…
A complete, beginner-to-production walkthrough of multi-region deployment: the many-kitchens pizza analogy and the 1990s-to-today evolution timeline (single data center, multi-server single site, mid-2000s CDNs, 2010s cloud regions, 2015+ compliance-driven multi-region), why the speed of light and two-thirds signal velocity through fiber make it a physics problem rather than a code…
A beginner-to-production deep dive into multi-cloud strategy — why teams run workloads across AWS, Azure and GCP, how the pipelines and data-replication flows actually work, the real trade-offs, and how organisations like Netflix, Spotify, Snap and large regulated banks combine clouds in practice.
A ground-up tutorial on the three pillars of observability — metrics, logs, and traces — from the shift out of monoliths into microservices, through OpenTelemetry, W3C Trace Context, structured logging, spans, sampling, exemplars, PromQL, the RED and USE methods, SLOs and error budgets, cardinality control, downsampling, HA and DR patterns…
A complete, beginner-to-production walkthrough of software observability: the 1960 control-theory origin of the word from Rudolf Kalman, the submarine and dashboardless-car analogies, and the 2010s distributed-systems pressure (Google, Twitter, Uber, thousands of containers) that forced the industry to move beyond classic monitoring; a monitoring-versus-observability comparison table explaining known-question dashboards versus…
A complete, beginner-to-production guide to the OWASP Top 10 – the world’s most influential web application security standard: what it is (a community-driven, evidence-based ranking of the ten most critical web application security risks), who owns it (the nonprofit Open Worldwide Application Security Project founded in 2001 by Mark Curphey),…
A beginner-to-production deep dive into OLTP vs OLAP — how transactional and analytical databases differ in storage layout, schema design, ACID guarantees, MVCC, columnar scans, MPP scatter-gather, ETL and CDC pipelines, CQRS, and the real-world architectures behind Amazon, Netflix, Uber, Swiggy, Flipkart and Indian banking systems.
A ground-up tutorial covering both the data warehouse and the data lake, side by side. From Bill Inmon coining “data warehouse” in 1988 to James Dixon coining “data lake” in 2010, through schema-on-write vs schema-on-read, ETL vs ELT, star / snowflake schemas, columnar storage, medallion (Bronze / Silver / Gold)…
A complete, beginner-to-production walkthrough of why every well-built login system stores password hashes instead of encrypted passwords: the 1962 MIT CTSS printer incident, Robert Morris Sr.’s 1970s Unix crypt-with-salt scheme, and the timeline through bcrypt (1999), PBKDF2 (2000), scrypt (2009), and Argon2id’s 2015 Password Hashing Competition win; the core motivation…