The Software Engineering Podcast with Fexingo: Code, Architecture, and Engineering Best Practices

Episode 54 of The Software Engineering Podcast dives into a real-world cost optimization story. Lucas and Luna walk through how a senior engineer at a mid-size SaaS company cut their AWS bill by 60 percent by migrating stateless workloads to spot instances. They discuss the engineering trade-offs: designing for interruption tolerance, using checkpointing and auto-scaling groups, and the monitoring...

Episode 53 of The Software Engineering Podcast dives into the maddening world of heisenbugs — bugs that disappear the moment you try to inspect them. Lucas and Luna walk through a real case: a production service that crashed once every 72 hours, but only under load. The team spent two weeks instrumenting, tracing, and finally caught a race condition in a Go channel that only triggered when the CPU...

Episode 52 of The Software Engineering Podcast with Fexingo tells the story of a single timezone handling bug at a travel-booking company that caused a cascading failure, losing over $2 million in revenue in a single weekend. Lucas and Luna break down how one engineer—Maya Chen—discovered the root cause was a misconfigured Olson database file, and the elegant fix she deployed using a small Go serv...

Configuration drift is one of those slow, silent killers in infrastructure. You patch one server manually, push a hotfix to another, and six months later your production environment is a unique snowflake that nobody fully understands. In this episode, Lucas and Luna walk through the story of a senior platform engineer named Priya at a mid-sized fintech company. Her team was spending roughly 30 per...

In episode 50 of The Software Engineering Podcast, Lucas and Luna explore the story of a senior engineer at a mid-sized SaaS startup who reduced deployment time from 12 hours to 11 minutes by implementing an ephemeral sandbox preview system. They break down the technical architecture: how the engineer used Kubernetes namespaces, a custom ingress controller, and a GitHub Actions pipeline to spin up...

In this episode of the Software Engineering Podcast, Lucas and Luna dive into a real-world case where a single engineer reduced database query latency by 99% by rethinking connection pooling. They explore the problem of connection storms, the trade-offs between pooling and direct connections, and how a simple configuration change transformed a struggling API into a high-throughput service. The epi...

In this episode of The Software Engineering Podcast, Lucas and Luna dive into the anatomy of a memory leak that took down a major trading platform for 45 minutes during peak market hours. They break down how a missing free() call in a C++ order-book module caused heap exhaustion, why the leak evaded detection for months, and the engineering fix—arena allocation with bounded lifetimes—that eliminat...

Lucas and Luna dive into a real-world incident where a seemingly innocent database query caused a full production outage at a mid-size e-commerce company. They walk through the sequence of events: a developer ran an unindexed join on a table with 12 million rows, which escalated into a table-level lock, cascading connection pool exhaustion, and a 47-minute downtime. The hosts explain how the query...

In this episode, Lucas and Luna explore a real-world case where a single engineer at a major e-commerce company slashed message queue latency by 80 percent. They walk through the original architecture — a RabbitMQ cluster handling 50,000 messages per second for order processing — and the bottleneck caused by per-message acknowledgments and database writes. The fix: a batching layer that collected...

Episode 45 tells the story of Sarah Chen, a backend engineer at a mid-size ad-tech company, who cut a high-throughput Go service's memory consumption by 70 percent by replacing the default garbage collector with arena-based allocation. The episode dives into Go's garbage collection behavior, the concept of memory arenas (inspired by C's malloc arenas and jemalloc), and how Sarah identified that he...

Episode 44 of The Software Engineering Podcast with Fexingo: Code, Architecture, and Engineering Best Practices. Lucas and Luna explore the story of a senior backend engineer at a ride-sharing company who used a genetic algorithm to optimize API request routing across hundreds of microservices. The engineer faced a classic NP-hard problem: route requests through a complex dependency graph to minim...

Episode 43 of The Software Engineering Podcast explores how property-based testing can dramatically reduce test suite execution time while catching edge cases that traditional example-based tests miss. Lucas and Luna walk through a real case where a senior engineer at a fintech startup replaced thousands of brittle unit tests with a handful of property-based tests, cutting the CI pipeline from 45...

In this episode of The Software Engineering Podcast, Lucas and Luna dive into chaos engineering — but not the abstract kind. They focus on a specific story: how a senior engineer at a mid-sized e-commerce company built a lightweight chaos simulation tool from scratch after existing solutions proved too heavy for their team. The tool intentionally injects latency into specific microservices during...

Luna and Lucas explore the story of how a single engineer at a mid-sized e-commerce company migrated a 15-year-old monolithic Java application to microservices over 18 months. The key? A strangler fig pattern that routed traffic incrementally, zero-downtime deploys using feature flags, and a custom gateway that handled the transition. They break down the specific techniques: how the engineer ident...

Episode 40 of The Software Engineering Podcast dives into monorepo CI optimization. Lucas and Luna explore how a single engineer at a mid-sized tech company slashed continuous integration from 45 minutes to under 8 minutes by implementing incremental builds and dependency caching. They break down the specific techniques: Bazel-style action caching, remote caching with a shared Redis store, and a c...

In this episode, Lucas and Luna dive into the story of a fintech startup that avoided a catastrophic outage during a critical payment system migration — thanks to a single feature flag. They break down how the engineering team used a kill switch to gradually roll out a new database schema, caught a silent data corruption bug in the canary phase, and toggled back to the old system in under 90 secon...

In this episode, Lucas and Luna explore how a single engineer at a mid-size SaaS company built a custom static analysis tool that automated 80% of code review comments. They break down the specific rules the tool enforced, how it was integrated into the CI pipeline, and the surprising cultural pushback the engineer faced. The episode includes a real-world example: a rule that caught unnecessary da...

Episode 37 of The Software Engineering Podcast with Fexingo dives into a specific operational win: how a senior engineer at a mid-size fintech company automated incident response runbooks, slashing mean time to resolution from over two hours to under thirty seconds. Lucas and Luna walk through the before-and-after — the chaotic Slack threads, the manual playbook that lived in a Google Doc, and the...

In episode 36 of The Software Engineering Podcast with Fexingo, Lucas and Luna dive into one of the most infamous hardware-induced software bugs in recent memory: the 2021 Facebook outage caused by a single bit flip. Lucas explains how a routine configuration change triggered a cascading failure that took down Facebook, Instagram, and WhatsApp for over six hours. He walks through the exact sequenc...

In this episode of The Software Engineering Podcast, Lucas and Luna dive into the story of a senior engineer at a mid-size SaaS company who cut their CI build pipeline from 40 minutes to 90 seconds. They walk through the specific bottlenecks: a monolithic Gradle build with unnecessary task dependencies, Docker layers being rebuilt on every commit, and a test suite that ran sequentially. The fix wa...

Episode 34 of The Software Engineering Podcast with Fexingo dives into a practical optimization story: how one engineer at a mid-sized SaaS company shrank a bloated Docker image from 2.1 GB to just 210 MB. Lucas and Luna walk through the specific techniques used — from switching to Alpine base images to eliminating layer bloat with multi-stage builds and removing unnecessary packages. They discuss...

Episode 33 of The Software Engineering Podcast with Fexingo. Lucas and Luna dive into the story of a senior engineer who inherited a monolithic ten-year-old codebase with zero tests and a single deployment causing multi-hour outages. Over six weeks, they systematically added integration tests, extracted domain modules, and built a CI pipeline that cut deployment failures by 90 percent. The episode...

In this episode, Lucas and Luna dive into a near-disaster at a mid-sized SaaS company where a single engineer prevented a cascading data loss by implementing a soft delete pattern. They walk through the specific scenario: a misconfigured database trigger that would have wiped thousands of customer records during a routine cleanup. The engineer's decision to use a tombstone column and a scheduled p...

In this episode of The Software Engineering Podcast, Lucas and Luna dive into a real-world case of consistent hashing preventing a production cascade failure. They break down how one engineer at a major streaming platform rearchitected a cache layer to avoid the thundering herd problem, reducing p99 latency spikes from 12 seconds to under 200 milliseconds during a regional outage. The conversation...

In this episode of The Software Engineering Podcast, Lucas and Luna dive into the practical world of FinOps — cloud financial operations. They explore how a mid-size SaaS company called DataNest slashed its AWS bill by 60 percent in just six months. Lucas breaks down the specific tactics: moving from on-demand to reserved instances, implementing automated right-sizing policies, and building cost-a...