Knowledge Planet: Old Dock's Tech Chronicles Zhihu: SamDeepThinking A technical manager who still codes heavily on the front line. From junior developer to tech lead, then tech manager, now leading the whole front‑ and back‑end development team—leveling up along the way. I have some insights on programming, career development, and tech management.
After working with four CTOs, the author highlights three valuable habits learned from three of them—systematic planning, staying hands‑on with code, and aligning technology decisions with business needs—that continue to shape his management approach today.
After years of writing code, the author shares three disciplined habits—anticipating non‑functional scenarios, structuring code to reflect business flow, and adopting spec‑driven development—to improve code quality and resilience in production systems.
The article explains that in Domain‑Driven Design a Repository should target the aggregate, not individual tables, because the aggregate defines a consistency boundary; having separate repositories for master and detail tables breaks this boundary, allowing inconsistent writes and bypassing the aggregate root’s validation.
The article explains that domain services are not optional in DDD but become necessary when aggregate roots cannot contain certain business rules, such as those requiring external data, batch processing, or rules that don’t belong to a single aggregate, and outlines principles for their proper use.
The article outlines three core architectural choices—channel isolation, a dedicated payment gateway, and robust callback handling with Redis and distributed locks—that together prevent a single payment channel failure from collapsing the entire payment platform.
The article walks through the evolution of Redis leaderboard architectures, covering why ZSets are used, handling same‑score ordering, seasonal resets, access patterns, synchronous vs asynchronous updates, big‑key and hot‑key issues, sharding with buckets, and data durability strategies.
The author argues that in the IT sector layoffs are driven by replaceability, not job title, so core developers and effective managers are retained while positions that can be removed with minimal business impact—often managerial roles—are more likely to be cut.
When migrating tens of billions of rows, the article explains how a simple progress‑tracking table and failure‑log table enable automatic checkpoint‑based resumption, stateless execution, and dynamic batch tuning without restarting or rewriting code.
The article explains why a large product cache moved from an in‑heap Caffeine cache to an off‑heap OHC solution, detailing serialization trade‑offs, per‑dimension cache configuration, singleflight loading, and the performance gains observed during high‑traffic promotions.
The article explains how candidates should showcase only the most relevant, deeply‑involved projects—detailing background, role, challenges, solutions, and impact—to demonstrate technical depth and decision‑making ability during a Java interview, while avoiding superficial or overly lengthy descriptions.
