Fireworks AI
Small (~100)
Mercury
Large (~1,300)
Best For
Fireworks AI
Best for: Engineers who want to work with ex-Meta AI infrastructure engineers on LLM inference
Mercury
Best for: Engineers who want product ownership and fast growth building startup banking infrastructure
Ratings
Fireworks AIMercury
4.2
4.3
Overall
3.3
3.8
Work-Life Balance
4.3
3.9
Culture & Values
4.2
4.0
Comp & Benefits
4.2
3.8
Senior Mgmt
4.0
3.9
Career Opps
👍 79% Recommend
👤 85% CEO Approval (Immad Akhund)
Culture Values
Fireworks AI only
🎧 Deep Work / Low Meetings
Mercury only
🎯 Direct Product Impact💎 Strong Comp & Equity
Shared
⚙️ Engineering-Driven🚀 Ship Fast & Iterate🧩 Wears Many Hats🌱 Learning & Growth
Pros & Cons
Fireworks AI
- World-class team of ex-Meta AI infrastructure engineers — technically very strong peers
- Working on LLM inference optimization which is one of the hottest areas in AI infrastructure
- Early-stage startup intensity with long hours expected and high performance bar
- Small team and rapidly evolving product means less structure, process, and career laddering
Mercury
- Strong talent density with smart, motivated teammates and genuine autonomy and ownership
- Great Place to Work certified — product-first mindset with meaningful scope for every engineer
- Still figuring out how to scale processes — expect some ambiguity and shifting priorities
- Work-life balance rated 3.8/5 — periods of higher intensity during rapid growth phases
Bottom Line
Fireworks AI
Choose Fireworks AI if you want to work with ex-Meta AI infrastructure engineers on cutting-edge LLM inference — but expect early-stage startup intensity and limited structure.
Mercury
Choose Mercury if you want product ownership, fast growth, and to build banking infrastructure for startups — but expect growing pains and occasionally intense workloads.
Open Roles
Fireworks AI — 28 jobs
💻 Engineering
9
💼 Sales / GTM
4
⚙️ Operations
2
👤 HR / People
1
⚖️ Legal
1
📣 Marketing
1
🧠 ML / AI
1
📋 Product
1
Mercury — 51 jobs
💻 Engineering
11
💼 Sales / GTM
9
⚖️ Legal
4
🎨 Design
3
📣 Marketing
3
📊 Data
2
💰 Finance
2
👤 HR / People
2
📋 Product
2
🧠 ML / AI
1
⚙️ Operations
1
🎧 Support
1
Summary
Fireworks AI scores 4.2/5.0 on Glassdoor with a 3.3 work-life balance rating. Mercury scores 4.3/5.0 overall with a 3.8 WLB. That’s a 0.1-point gap on overall satisfaction.
Both companies share these culture values: Engineering-Driven, Ship Fast & Iterate, Wears Many Hats, Learning & Growth. Fireworks AI also emphasizes Deep Work / Low Meetings. Mercury also emphasizes Direct Product Impact, Strong Comp & Equity.
On the hiring front, Fireworks AI has 28 open roles and Mercury has 51 open roles.