Duolingo | Full-time | Multiple roles | $177K-$300K | NY and Pittsburgh | ONSITE

Our mission is to develop the best education in the world and make it universally accessible. Our culture is eng-driven, friendly, and very data-driven thanks to our large userbase. More info about working as an engineer at Duolingo here: https://www.youtube.com/watch?v=WThT8sufdBE

Tech stack: (frontends) Swift/Kotlin/TypeScript, (backend) Python/Kotlin/Postgres/Dynamo, (infra) AWS/k8s/Terraform.

We're always hiring for engineers. A few roles below:

Senior Engineering Manager, Monetization: https://careers.duolingo.com/jobs/8414653002

Senior Android Engineer: https://careers.duolingo.com/jobs/8217266002

Engineering Manager, Chess: https://careers.duolingo.com/jobs/8385137002

Senior iOS Software Engineer: https://careers.duolingo.com/jobs/8318257002

Base salary: $200K-300K for Senior Eng Manager, $177K-$240K for the others (+equity).

Perks: free lunch, 2-week winter break + 20 days of flexible time off.

Fullstory | Remote (US), Atlanta, London, Bogotá, Czechia | https://www.fullstory.com/

Fullstory provides privacy-preserving session replay and analytics for websites and mobile apps. Our session replays are nothing short of magical - they look almost like a video of the user's screen (with private details redacted) - and the combination with analytics creates eye-opening insights.

Remote (US):

* Senior Software Engineer, Android - $160~170k - Java, Rust, Kotlin, Compose Multiplatform - https://www.fullstory.com/careers/jobs/3be8b5f8-b05c-4221-b9...

* Senior Software Engineer, iOS - $160~170k - Objective-C, Swift, SwiftUI - https://www.fullstory.com/careers/jobs/1c9234a4-af67-428d-91...

Atlanta, USA (1 day per week in office):

* Software Engineer, Digital Experience Analytics - Go, TypeScript, GCP - https://www.fullstory.com/careers/jobs/a786962d-68c1-48fa-8b...

* Software Engineer, Subtext - AI agents, Go, TypeScript - https://www.fullstory.com/careers/jobs/073bfc41-0ac6-4e59-a5...

We have additional engineering and product design roles open in Colombia and Czechia as well as other roles in product management, sales, HR, support, and solutions in the US and UK. See the full list at https://www.fullstory.com/careers?ashby_jid=bce3fcba-6b80-43...

For US roles, you can expect regular raises & bonuses, equity, and benefits including: health insurance, 401k matching (Vanguard), annual learning stipend, unlimited PTO, parental leave, and more. I take about 4-5 weeks vacation a year, in addition to ~3 weeks worth of company holidays (federal holidays + the week of Christmas to New Years.)

Folks in other countries can also expect a strong benefits package, but I'm not as versed on the details.

Additionally, you get a 5-week sabbatical after 5 years of employment - I took mine about a year ago, and it was fantastic.

To apply, please submit your info on the website, and our recruiting team will get in touch with you. If you have questions, feel free to reply here or contact me directly. (I'm an engineer on the iOS team, but I'll do my best to answer questions.)

x2A | NYC, NY, USA | ONSITE | https://x2a.tech

We are actively looking for multiple software developers or software engineers to join our team (in the office, 5 days/week). These positions primarily focus on our 5off software product (puzzles/games).

There is zero expectation for you to be proficient in all aspects of the tech stack. We are looking for people who know some of these technologies and are excited to share their expertise while developing their skills and learning new things.

We welcome candidates at any experience level, with or without academic qualifications. For junior candidates, do not hesitate to share related personal projects.

Tech stack:

  - Languages: Python, Typescript, Swift, Rust, C++.
  - Backend: SQLAlchemy, PostgreSQL, Litestar.
  - Frontend: Svelte, Tailwind.
  - Mobile: Swift, SwiftUI.
  - Cloud: AWS, AWS CDK.
  - DevOps: Gitlab.

Compensation: 115k-170k based on experience and skills.

More https://x2a.tech/careers/openings/ for more details and how to apply.

Quidient | Software, Mobile, QA, IT, TPM | HYBRID (Columbia, MD) | Full-time | https://quidient.com/careers

About us:

The physical world is still largely unstructured. Quidient is building a new foundational category: Generalized (5D) Scene Reconstruction (GSR). Our API-first platform turns real-world environments into measurable, queryable digital assets—powering applications across defense, infrastructure, and spatial AI.

We work at the intersection of AI, physics-informed models, large scene/world models, and real-time 3D systems.

Open Roles: - Software Engineer, Full Stack (Product / Web) • Build polished web + desktop interfaces on top of our 5D reconstruction engine, including interactive 3D workflows and API-driven experiences.

- iOS Engineer (Opening Next Week) (Mobile / 3D / AR) • Build high-performance iOS applications for real-world capture and reconstruction using Swift, Metal, ARKit, and CoreML in compute-heavy, low-latency environments.

- Senior SDET (iOS / Performance / Automation) • Own quality and release readiness for iOS edge applications, leading automation, CI/CD, and deep performance profiling across CPU/GPU/memory/thermal constraints.

- IT Systems Administrator • Build and scale internal IT for a deep-tech company, supporting cloud identity, MDM, security posture, GPU-heavy engineering systems, and compliance-driven environments.

- Technical Project Manager (Product Development) • Keep complex, cross-disciplinary engineering work moving—owning sprint operations, roadmap hygiene, stakeholder alignment, and execution clarity alongside engineering leadership.

Team & Setup: Small, senior team. Real customers. Real physics. Hybrid roles based out of our Columbia, MD technology center. Company is profitable and doubling this year.

SpruceID (YC W21) | REMOTE (US-Based Preferred) | Full-Time | spruceid.com

[NEW ROLE FOR EXCEPTIONAL NEW GRADS OPEN]

Spruce lets users control their data across the web. Instead of users logging into platforms, we believe platforms should request to access data vaults controlled by users.

The demand for trusted digital ID is accelerating as AI deepfakes begin to destroy most of the ways we use to verify identity today. How private or secure is it to hold your driver's license or passport up to a webcam to get a bank account? Was it ever private or secure? Stable diffusion can break so much of this already. Society will need trusted digital IDs and credentials. Our mission is to allow them to be controlled by individuals, with safeguards to prevent descents into surveillance states and checkpoint societies.

We are the main implementers of category-defining initiatives such as the digital ID program for the California DMV, and the verifiable digital credentials program in Utah. We are private sector participants in NIST's National Cyber Security of Excellence initiative for privacy-preserving digital ID.

We are hiring skilled engineers who care about making a real impact in improving public services, digital autonomy, and user privacy for the world. We work closely with public sector agencies, and have high regard for public servants. We have a strong engineering and customer-oriented culture, and are not simply a SaaS product or AI wrapper. Our roles are not for the faint of heart: you will be expected to work hard and learn a lot in this role.

Our engineers are ambitious to get outcomes for our customers and their constituents. On any given day, they may write great Rust/C#/TypeScript, deal with mainframe dumps, read policy documents, respond to technical RFIs/RFPs, manage on-prem environments, implement new NFC + Bluetooth protocols in Swift/Kotlin, create CI/CD processes that enforce W3C accessibility guidelines and i18n requirements, rewrite lost specs from disassembled binaries, figure out stablecoin payments, and design new protections for public key infrastructure. It is a team effort, and people with T-shirt shaped skills are able to collaborate and learn a ton from each other every day.

We are interested in candidates who want to be proud of the meaningful impact they make for society, even if it takes time to get right. This is not the right job for someone who wants to "join a cool new AI startup" that implodes or exits in under a year.

See our roles here: https://jobs.lever.co/sprucesystems/

Return | REMOTE | Software engineer backend (Go/Golang) | Full-time

Return (https://return.energy) is hiring a software engineer to work on platforms that accelerate the transition to carbon-free energy. Return’s main activity is building and operating industrial-scale Battery Energy Storage Systems. Our operations are located in the Netherlands, Germany, Belgium, and Spain. You will make a measurable, country-level impact on the transition to renewable energy. Return recently raised €300M to support its growth.

While we employ more than 120 people, Return’s technical team remains small with 13 members. Our platform automates processes in energy storage, monitoring, market optimization, sales, project management, procurement, construction, and customer service.

During the first three years of operation, we laid the foundation for our platforms, and we are ready to scale up. This is why we are looking for an experienced software engineer.

Your primary focus will be to further develop our battery virtualization platform, enabling customers to use slices of battery capacity distributed across our fleet of industrial-scale batteries.

Our tech stack and toolset are straightforward: Go, Python, Ruby, PostgreSQL, TigerData, dbt, Dagster, Grafana, Terraform, and self-hosted plus cloud compute. We keep meetings to a minimum to provide at least five hours of uninterrupted coding time per day. We conduct code reviews and apply both automated and manual testing. Our web apps and platforms are often deployed multiple times per day.

Return has offices in Amsterdam, Berlin, Brussels, Hamburg, Munich, Madrid, and Stuttgart. We are very open to remote work as long as you live in the EU. Our hiring process is swift but thorough: a brief call to get acquainted and discuss finances, followed by one or more technical interviews, and a paid visit to Amsterdam to meet the team.

The tech team members have co-founded several companies and have worked with remote development teams since 2008, and they will personally guide you through most of the recruiting process (there is no recruiter involved).

We aim to hire you in February or March ultimately.

Apply here: https://jobs.polymer.co/return/37860

BuildForever | On-site (SF, NY) | Full-time

We’re a small team of creative builders crafting consumer products that feel personal, magical, and deeply human. We build for ourselves first, with the belief that what delights us will resonate with millions more. We imagine a new golden age of consumer software - crafted with heart, emotion, and taste. Small, inspired teams building things that feel lovingly made, purposeful, and joyful to use. If that sounds like your happy place, you’ll fit right in.

We have several positions available. Please send us a note at careers@buildforever.com with a short intro and links to what you’ve built (systems, repos, tools, prototypes, side projects). We care more about your taste, technical creativity, and product intuition than resumes.

Backend Engineer - https://ambiguous-thunder-400.notion.site/Backend-Engineer-2...

ML/AI Engineer - https://ambiguous-thunder-400.notion.site/ML-AI-Engineer-2aa...

Product Engineer - https://ambiguous-thunder-400.notion.site/Product-Engineer-2...

Social Growth Lead - https://ambiguous-thunder-400.notion.site/Social-Growth-Lead...

Stack Backend: Python, FastAPI, TypeScript, Postgres/SQLModel, Redis, Cloud Run. Frontend: Swift, UIKit, React.

Beacon AI | San Carlos, CA | Hybrid (On-Site) | Full-Time | www.beaconai.co

Beacon AI builds intelligent systems that make aviation safer and more autonomous. We’ve completed multiple DoD programs and are expanding our team with exceptional technical leaders to push the boundaries of human-machine collaboration in the cockpit. At Beacon, you will lead by example, mentoring and growing a small team of talented engineers (typically 1–2 to start) while staying hands-on in design and execution. You’ll help shape critical systems that advance aviation safety and autonomy, working alongside a team that values effort, creativity, and accountability.

We’re hiring Lead Engineers with 5-9 YOE who love solving complex problems. At Beacon, you’ll own your work end-to-end, from prototype to deployment, and literally see your code take flight in real world aviation environments! Roles:

++ Lead iOS Engineer [Tech Stack: Swift, SwiftUI, UIKit, Mapbox]

++ Lead Infra/Backend Engineer [Tech Stack: AWS]

++ Lead WebApp/FrontEnd Engineer [Tech Stack: Python, Typescript, React]

++ Lead Autonomy/Robotics Engineer [Tech Stack: C++, Python, iOT]

Join us at beaconai.co/careers. Mention in the application that you saw our post on HN.

Pushscroll | Full-Stack Mobile Engineer (KMP) | REMOTE (GMT-3 to GMT+4)

We make people do push-ups before they can scroll addictive apps. Our dream is to help replace doomscrolling with exercise, which we verify through camera pose detection.

500k+ downloads, bootstrapped and profitable, very quickly growing.

Looking for someone strong in Kotlin Multiplatform + Compose Multiplatform + Swift/SwiftUI who works independently, uses AI to ship fast, and can implement a pixel-perfect Figma design.

Bonus: Supabase, Amplitude, native Android/iOS knowledge (e.g., Screen Time).

Small team, work directly with founders, long-term role. We’ve got big plans to make Pushscroll the app of the year, and there are a lot of challenging problems to get there.

Reach out: contact@pushscroll.com