---
title: "Gossip Glomers"
description: "Gossip Glomers is a series of distributed-systems programming challenges created by Fly.io and Kyle Kingsbury, author of Jepsen, to connect practical coding with distributed-systems theory. Each challenge supplies a workload, a simulated network that can partition or delay messages, and a Jepsen-based verification system; participants write the node binary. The progression covers Echo, a coordination-free unique ID generator, fault-tolerant broadcast, a grow-only counter over Maelstrom’s sequentially consistent key/value store, a Kafka-like replicated log over a linearizable store, and totally available transactions across consistency levels. Initially developed as a resume-blind work-sample evaluation for staff-engineer hiring, the challenges were released publicly because the creators found them too useful and enjoyable to keep internal, with the hardest challenge remaining part of Fly.io’s staff-engineer evaluation."
---

# Gossip Glomers

[Fly.io](https://yomu.fyi/company/fly-io) · Feb 22, 2023

**Type:** Announcement

## Summary

Gossip Glomers is a series of distributed-systems programming challenges created by Fly.io and Kyle Kingsbury, author of Jepsen, to connect practical coding with distributed-systems theory. Each challenge supplies a workload, a simulated network that can partition or delay messages, and a Jepsen-based verification system; participants write the node binary. The progression covers Echo, a coordination-free unique ID generator, fault-tolerant broadcast, a grow-only counter over Maelstrom’s sequentially consistent key/value store, a Kafka-like replicated log over a linearizable store, and totally available transactions across consistency levels. Initially developed as a resume-blind work-sample evaluation for staff-engineer hiring, the challenges were released publicly because the creators found them too useful and enjoyable to keep internal, with the hardest challenge remaining part of Fly.io’s staff-engineer evaluation.

## Context

The creators wanted to bridge practical distributed-systems experience and academic theory. The challenges also grew out of Fly.io’s need for a stronger staff-engineer hiring evaluation based on work samples, after earlier attempts to design distributed-systems tests did not feel right.

## Approach / What changed

The series uses Maelstrom to run participant-written distributed systems over a simulated network. Workloads send messages and enforce constraints, the network injects partitions or delays, and Jepsen verifies each challenge’s consistency and availability requirements.

## Takeaways

- Maelstrom simulates toy distributed systems and network failures locally, while Jepsen checks the consistency and availability constraints required by each workload.
- The progression moves from Echo and coordination-free unique IDs through fault-tolerant broadcast, a grow-only counter, a Kafka-like replicated log, and totally available transactions.
- The challenges began as a resume-blind staff-engineer evaluation at Fly.io and were later released publicly; the hardest challenge remains part of that evaluation.

**Tags:** [Distributed Systems](https://yomu.fyi/topic/distributed-systems), [Jepsen](https://yomu.fyi/topic/jepsen), [Maelstrom](https://yomu.fyi/topic/maelstrom)

- Source: [Fly.io](https://fly.io/blog/gossip-glomers)
- Source URL: https://fly.io/blog/gossip-glomers
- Ingested by Yomu: 2026-09-02T12:00:52.864Z

[Read original post](https://fly.io/blog/gossip-glomers)