Reasoning agents have quietly crossed a threshold. In just the past few months, models gained the ability to choose and chain tools, turning them from text summarizers into systems that can actually reason, act, and adapt. For defense missions, that shift is enormous.

Vannevar CEO Brett Granberg explains why the o1 –> o3 leap changed everything, how a task that once required 40 analysts a month now runs in 20 minutes, and why agents are more than “chatbots with tools.”

We cover:

• Why tool use is the real step-change
• Concrete defense use cases
• The playbook for building with agents: model-agnostic, tool-first, and mission-driven
• How tech-enabled services could upend billions in prime contracts
• The unsolved problems: model evaluation, UX, and hallucinations
• What an “agent-native” team looks like, and how to build one

Outline

• 00:00 The inflection point
• 00:36 What are reasoning agents?
• 03:38 Why now?
• 04:46 New missions unlocked
• 05:45 Vannevar case study
• 09:17 The last 20% problem
• 12:18 Ship fast, don’t break infra
• 16:18 The agent product playbook
• 20:13 Agents x sensing grid
• 23:23 Be model-agnostic or lose
• 26:19 3x Better, not 10% better
• 28:24 Impact on tech-enabled services
• 32:18 Paths forward for startups
• 34:05 What’s real today
• 36:10 Picking models that win
• 38:22 Unsolved challenges
• 39:15 Hiring an agent-native team

Vannevar CEO Brett Granberg walks through his founder journey, from the first days to a $1.5B valuation. We cover his lessons learned and key decisions he made along the way: why Vannevar is not dual-use, how to think about defense TAM, why you should reference-check your investors, and building credibility in the early days. Finally, Brett explains what shifts once you do raise venture capital – how incentives and expectations change, and why managing founder psychology and energy becomes part of the job if you want to build something durable.

Highlights

-- The $16K bill that triggered the leap
-- Why defense-only > dual-use for actually shipping value
-- How to talk TAM in defense (and how not to)
-- Building credibility from zero with “part-time hooks”
-- Reference-checking your investors
-- Founder psychology and burnout, from survival mode to scale

🔗 Careers at Vannevar: https://vannevarlabs.com/careers/

Outline
00:00 The very beginning
01:08 Deciding to drop out of school
02:24 Making the leap
03:23 The early co-founder partnership
05:46 Product development before customers
07:26 Fundraising then vs. now
09:39 The dual use trap (and why we avoided it)
12:33 How to think about defense TAM
15:47 Recurring revenue in defense
18:03 Screening investors
20:26 Building credibility as an unknown quantity
22:13 Biggest surprises about being a founder
24:08 Mindset shifts from zero to $1.5B

Vannevar CEO Brett Granberg explains the ideology behind one of our core operating principles: “Leave your ego at the door." Brett breaks down the difference between confidence and ego, and why “nice guys don’t close big deals” is lazy thinking that hurts mission outcomes.

We get practical: how to hire high-agency people, how to spot toxic ego in interviews, when a strong personality becomes net-negative for the team, why learning rate is Brett’s personal success metric, and how to give high-conviction builders room to run without letting them steamroll the org. Brett also shares the operating principles that took Vannevar from 50 to 250+, the cross-functional model that 10x’s outcomes, and which roles he thinks are the hardest to hire.

We discuss:

• Confidence vs. ego (and why ego is often a lack of self-confidence)
• The “net output” test for keeping or moving on from a hire
• Red flags in interviews
• How to structure teams for high-conviction bets without chaos
• Scaling culture around specific outcomes as opposed to generic values

Click here to watch a video of this episode.

Outline
00:00 What ego means in high performance teams
00:25 Self-confidence vs. ego
01:56 The line between confidence and toxicity
04:37 Screening for ego in interviews
09:20 Do founders need ego to succeed?
11:07 Managing your own ego as a leader
14:59 Can you coach out unhealthy ego?
16:52 High agency leadership without steamrolling
19:14 Vannevar's interview process
21:59 Profile of first five hires
24:29 Hiring mistakes and lessons
26:31 Core operating principles
28:44 Scaling culture from 50 to 250+ people
33:25 Most difficult roles to hire for

How do companies know which products to build? What are traits of a 10X product leader? Should national security startups pursue a portfolio of bets or take a couple concentrated big swings? What does it look like to balance buyer vs. customer demand in defense? In this episode, CEO Brett Granberg shares how Vannevar has navigated these questions while making strategic product bets. We explore Vannevar's product evolution, from early failures to recent strategic moves.

We're hiring: https://vannevarlabs.com/careers/

Click here to watch a video of this episode.

Outline
00:00 Introduction to building products
00:22 Product bet: Economic competition
02:39 Failed products and lessons learned
04:44 Recognizing local vs. global maxima
06:03 Handling user vs. buyer demand
07:31 High conviction product ideas
09:09 Customer feedback timing
10:33 Structuring product teams
12:10 Portfolio vs. concentrated bets
14:19 Scaling product approach
15:36 Most exciting new product areas
16:55 How to hire product leaders
18:05 Innovation boundaries
19:29 Build vs. buy decisions
21:15 10x product leader traits

In this episode, learn how defense companies can close deals faster and build better products by getting business development and engineering on the same page. Vannevar CEO Brett Granberg explains why engineers should be in the room early, how forward deployed engineers shape both products and customer trust, and why time on-site with users drives the best results. Brett and Hayley also discuss avoiding the “services trap,” how to balance conviction with customer needs, and why cross-functional teams consistently win the largest defense deals.

Outline
00:00 What is the ideal BD-engineering relationship?
02:57 Indicators of broken partnerships
04:23 When to bring engineering into sales
05:35 BD involvement in product decisions
07:15 Balancing conviction with customer needs
09:03 Avoiding shiny object syndrome
10:36 Processing customer feedback
13:23 Forward deployed engineer model
15:06 What it means to be a "product company" vs. a "services company"
18:00 When BD goes rogue
20:20 Leadership team dynamics
22:09 Building trust across functions

In this episode of In the Arena, Vannevar CEO Brett Granberg breaks down the shift from building software-only tools to integrated hardware-software systems. He shares why defense startups need to deliver complete systems (as opposed to just components), how hardware forces a different pace of iteration, and why real-world deployments – failures and all – are the only way to validate products.

We cover lessons from Vannevar’s RF sensing venture, the structural challenges of defense acquisition, and what it really takes to move fast in hardware while staying mission-first.

CHAPTERS
00:00 Intro
00:19 Do defense companies need to build both hardware and software?
01:56 Deciding to build hardware as a software-first company
03:45 Building exquisite systems vs. smaller, attritable nodes
05:38 Differences between hardware and software builders
07:15 How to learn how to build hardware
09:27 How does the government customer shape how you build hardware products?
13:08 How to build an integrated system
14:26 Scaling software vs. hardware companies
16:16 Aligning incentives when team cadences are different
18:01 Building hardware as a remote-first company
19:28 Lessons defense primes could learn
22:12 The unexpected
24:04 Build vs. buy considerations

Watch a video of this episode

In the first episode of In the Arena, Vannevar CEO Brett Granberg discusses what it really means to build technology for the national security mission.

They discuss Brett’s personal path from consulting into defense, what led him to co-found Vannevar, and why working in public service can be both meaningful and urgent.

The conversation explores:

• Why commercial tech doesn't always translate to defense
• What motivated the founding of a new kind of defense tech company
• How Vannevar builds agentic AI and deployable tools for mission users
• The importance of public service in a representative democracy
• Why the current geopolitical moment, especially competition with China, demands a new generation of engineering talent

Whether you're an engineer curious about working in defense, a policymaker thinking about tech adoption, or someone just trying to understand this evolving space, this episode offers a candid look at the mindset and mission behind Vannevar.

• (00:00) - Introduction
• (00:29) - Starting in defense
• (02:21) - A message to defense skeptics
• (06:12) - Why now?
• (09:35) - How will defense tech change over the next decade?
• (13:09) - Misconceptions about defense tech
• (14:39) - Defense startups vs. big tech companies
• (16:06) - Defense startups vs. defense primes
• (18:45) - Why is deterrence important?
• (20:34) - What would surprise someone about Vannevar?