In-depth technical writeups by Tamirat Fereja on building production NestJS microservices, optimizing database performance, managing distributed state, and designing scalable APIs.
Backend Systems Engineer specializing in NestJS, TypeScript, microservices, Apache Kafka, PostgreSQL, Redis, and distributed systems. Based in Ethiopia.
How I approached the challenge of bringing dental clinic operations into one connected platform—connecting patient records, appointment lifecycles, FDI treatment charting, invoicing, SMS communication, and DHIS2 public health reporting.
A comprehensive deep dive into PostgreSQL performance engineering—exploring how indexes, query plans, statistics, row-level locks, MVCC, write amplification, and access patterns interact in high-scale backend systems.
A software engineering deep-dive into building a modular, multi-timeframe day trading system in Python using MetaTrader 5 APIs, weighted confluence scoring, pending order pipelines, and strict risk validation gates.
How I think about choosing between Redis, PostgreSQL, and Kafka when designing distributed backend systems. Three technologies, three fundamentally different jobs, and a decision framework for choosing the right tool.
How Materialized Paths provided a much better read-oriented structure for an eLearning platform with 10,000+ learning objects, and the trade-offs between adjacency lists and materialized paths for hierarchical data in PostgreSQL.
How I think about Redis caching best practices including cache-aside patterns, invalidation strategies, stampede prevention techniques, and consistency models for NestJS and PostgreSQL-backed applications.
How I used PostgreSQL row-level locking to prevent race conditions when multiple users attempted to enroll in a limited-capacity cohort at the same time.
Architecting an asynchronous, scalable certificate generation system using Node.js, Puppeteer for PDF rendering, Kafka for job orchestration.
How to approach bidirectional calendar synchronization using OAuth2, Google Calendar APIs, event-driven webhooks, loop-prevention metadata, and asynchronous state reconciliation.
A deep dive into managing high-cardinality hierarchical data using PostgreSQL materialized path trees, NestJS TypeORM integration, raw SQL single-query descendant reordering, and Redis scan cache invalidation for sub-50ms query latency.
Architectural blueprint for decoupling distributed services using NestJS microservice transport with Apache Kafka topic partitioning, consumer group rebalancing, and idempotent event handlers.