JustBacked · October 2026 · Edition 1

Breakout Series B Companies to Join

The 25 most promising Series B startups that raised in the last 180 days and are hiring now, ranked on hiring momentum, round strength, investors and traction. How we rank.

The top 25 Series B companies

1
Mariana Minerals
Series B · $310M · Houston · Andreessen Horowitz, Greenoaks
44 new roles / 30d88 roles89
2
Gimlet Labs
Series B · $300M · San Francisco · Andreessen Horowitz, Emergence
5 new roles / 30d16 roles86
3
Cowboy Space
Series B · $275M · San Carlos · Andreessen Horowitz, Index Ventures
57 new roles / 30d78 roles86
4
OpenRouter
Series B · $113M · New York · Andreessen Horowitz, Menlo Ventures
12 new roles / 30d28 roles84
5
Proxima Fusion
Series B · $470M · Munich · Balderton, Lightspeed
23 new roles / 30d54 roles84
6
Wispr Flow
Series B · $280M · San Francisco · 8VC, Forerunner
6 new roles / 30d30 roles83
7
Augustus
Series B · $180M · San Francisco · Creandum, QED Investors
5 new roles / 30d8 roles83
8
Confido
Series B · $55M · New York · Insight Partners, Y Combinator
13 new roles / 30d37 roles82
9
Firecrawl
Series B · $75M · San Francisco · Y Combinator
12 new roles / 30d33 roles81
10
David
Series B · $250M · New York · Greenoaks, ICONIQ
12 new roles / 30d34 roles81
11
Quartermaster AI
Series B · $100M · Arlington · BoxGroup, Insight Partners
10 new roles / 30d19 roles79
12
Efficient Computer
Series B · $97M · Pittsburgh · BoxGroup, Union Square Ventures
7 new roles / 30d23 roles79
13
Parallel
Series B · $100M · Palo Alto · Index Ventures, Khosla
8 new roles / 30d26 roles78
14
TensorWave
Series B · $350M · Las Vegas
32 new roles / 30d64 roles78
15
Dwelly
Series B · $95M · London · General Catalyst
11 new roles / 30d26 roles78
16
Tandem Health
Series B · $100M · Stockholm · Northzone
28 new roles / 30d71 roles78
17
Ema
Series B · $77M · Mountain View · Accel
8 new roles / 30d37 roles76
18
Deep Infra
Series B · $107M · Palo Alto · Felicis, NVIDIA
9 new roles / 30d20 roles75
19
Meshy AI
Series B · $400M · Sunnyvale · Matrix Partners
6 new roles / 30d25 roles75
20
Rainmaker
Series B · $100M · El Segundo
9 new roles / 30d25 roles75
21
Amca
Series B · $300M · El Segundo · Andreessen Horowitz, Founders Fund
13 new roles / 30d51 roles75
22
Armada
Series B · $230M · San Francisco · 8VC, Founders Fund
9 new roles / 30d40 roles74
23
fomo
Series B · $75M · New York · Benchmark, Index Ventures
4 new roles / 30d8 roles73
24
Coram AI
Series B · $35M · Sunnyvale · 8VC, Battery Ventures
26 new roles / 30d50 roles71
25
Fractile
Series B · $220M · London · 8VC, Accel
4 new roles / 30d39 roles70

How we rank

Each month we score every startup that closed a venture round (pre-seed through Series C) in the previous 180 days, has at least 3 open roles, has raised under $2B in total and has fewer than 1,000 people. The score runs from 0 to 100 and mixes five signals:

Hiring momentum (30%). New roles posted in the last 30 days, relative to team size and in absolute terms, from the company's own hiring system. Companies closing more roles than they open are marked down.
Round strength (25%). How the round compares with other rounds at the same stage. A $15M seed is a strong signal; a $15M Series B is not.
Investors (20%). Whether a top-tier firm (Sequoia, a16z, Accel, Benchmark, Founders Fund, Khosla, Index, General Catalyst, Y Combinator and about 50 others) backed the company, otherwise how many investors did.
Traction (15%). Crunchbase rank, which reflects web traffic, news coverage and activity.
Freshness (10%). How recently the round closed. New money means new headcount plans.

The list is published on the 1st of each month and doesn't change afterwards; open-role counts are live. It's a signal of momentum, not an endorsement or a guarantee. Nobody pays to be on it.

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