Changelog
What changed, and when
Significant content changes, newest first, dated from the site's version history. Styling and infrastructure changes are left out.
- Merged thin pages into fuller ones: each concept’s in-depth material is now a section of the concept page, the six interviewer types are one interviewer guide, and company questions that repeated a main problem now appear as “How companies ask this one” on that problem’s worked solution. Old addresses redirect.
- Rewrote the titles of 61 Go lessons and 29 concept pages so each says what that page covers.
- Practice tools, quizzes and revision roll-ups stay available but are no longer listed for search engines.
- Worked examples added to The five stages and Where’s the slack?; fuller model answers for the Amazon flash sale and Microsoft collaborative editor questions; runnable examples, pitfalls and complexity tables added to the Go lessons on constants and iota, valid parentheses, cycle detection, sliding windows and the final interview checklist; the concepts index now shows what each concept costs and the order to read them in.
- Added this changelog, an editorial and AI-use policy on the about page, and a “Last reviewed” date at the top of lessons.
- New concept pages: API gateway vs load balancer vs reverse proxy, cache write strategies, Redis vs Memcached, isolation levels, and optimistic vs pessimistic locking.
- New Go lessons: worker pools, the sync package, mutex vs RWMutex, and interview questions for experienced developers. New problem: a distributed message queue.
- Added answers to commonly searched questions on existing concept pages.
- Model answers on problem pages are now part of the page rather than loaded afterwards, and each problem has an introduction.
- New interview guides in the Learn section, and title fixes across the site.
- Revision pages show their answers in the page, and every quiz set is linked from its section.
- Added the system design cheat sheet.
- Expanded the connection pooling concept, the company pages, the practice modes and the Go topic overviews.
- Accuracy pass: current Go install and go.mod versions, and corrected wording on AfterFunc, write-through caching, Retry-After, consistent hashing, semi-synchronous replication and queues.
- Company questions now link to their related problem, worked solution and concepts.
- Improved ten Go and system design pages that readers were searching for.
- Launched the Go track: reviewed lessons, runnable examples, and coding challenges checked by tests.
- The site was renamed Dev Skills, matching the domain.
- Copy-edited all learning content and fixed technical errors found in review.
- Added the privacy policy, terms and contact pages.
- Rewrote the content in plain English and filled coverage gaps in the concepts.
- Added a worked solution for every problem, and a whiteboard for the blank-page practice mode.
- Started the Go track.
- First version: the five-stage system design method, concepts in learning order, practice problems and company-style questions.
Spotted a mistake? Every page has a “Report a mistake” link, or see contact.