Top 8 IoT Software Development Companies to Hire in 2026

Connected products are no longer defined by hardware alone. A lock, badge reader, or wearable depends on the software behind it: how it sets up devices, handles dropped connections, and manages access over time. For most buyers, choosing an IoT partner is now a software decision. However, the wrong choice shows up late, when a promising pilot can’t scale into a real product.

This guide compares 8 top IoT software development companies that build connected products, not just apps. Each vendor is reviewed by Clutch rating, connected-device depth, and best-fit use case, so you can match a partner to the part of the stack where your team needs the most support. The list includes end-to-end builders like Axon that span devices and apps; firmware-first teams like Integra Sources and iomico; and app-heavy firms like Mercury Development.

Why the software layer now decides your IoT project

There were 21.1 billion connected devices in 2025, according to Statista. Hardware is no longer the biggest challenge. The harder work now sits in the app and cloud layer, which manages setup, credentials, offline use, and the tools operators rely on every day.

This matters most in access products. The smart lock market reached $3.23 billion in 2025 and is expected to reach $6.61 billion by 2030, with a 15.4% CAGR. New standards like Matter and Thread 1.4 are moving more work into software. Devices can join networks without a separate hub, so the development team must handle credentials, offline entry, and support across different ecosystems.

This makes the wrong partner costly. A vendor that only builds the app, without understanding how the device works, can leave the product stuck at the pilot stage. A connected door, badge, or pod must still work when the network goes down. The companies below are ranked by how much of that full chain they can own.

How to choose an IoT software development partner

Use these criteria to compare IoT software development companies: 

• Device-to-app ownership. One team should handle firmware, cloud, and mobile to prevent the product from breaking during handoffs. Axon is a strong example here, delivering connected products through one accountable team.

• Access and credential engineering. Offline PIN entry, mobile keys, revoked access, and audit trails require real access-control experience. Salt & Pepper has delivered smart access control systems end-to-end.

• Embedded and protocol depth. BLE, RFID, Wi-Fi mesh, and low-power firmware are often what separate shipped products from stalled pilots. Integra Sources and iomico both work deeply at this layer.

• Security and compliance posture. Certified processes matter when the product controls a physical entry point or handles sensitive data. Lemberg Solutions holds ISO 27001, ISO 9001, and ISO 13485 certifications.

The top IoT software development companies at a glance

This list includes Axon for connected products and smart access, Salt & Pepper for access and wearable builds, Integra Sources for embedded and firmware work, iomico for low-power wireless firmware, Lemberg Solutions for embedded and edge AI, SumatoSoft for IoT platforms and smart locks, Mercury Development for mobile and connected-device software, and Concepter for consumer smart hardware. 

Compare them side by side using the table below.

Axon: one team from device to app

Axon is one of the top IoT software development companies for end-to-end access products, with support that continues after launch. Founded in 2012, the company has a 4.8/5 Clutch rating across 42 reviews, 130+ completed projects, and 140+ engineers. Its portfolio covers smart locks, automotive systems, wireless audio, charging stations, and wearables.

Three production cases demonstrate its depth of access. TaskPod is a platform for private workspace pods in airports and shopping centers, built with offline PIN entry, KAS smart keys, and duration-based Stripe billing. A 10-person Axon squad delivered it end-to-end. Izy supports wireless electronic access control for business centers through Salto, with web, iOS, and Android built together. Nakipower handles QR code unlocking and multi-wallet payments across more than 2,000 rental points in Europe.

Why choose Axon:

• One accountable team owns device integration, cloud, and both mobile platforms, keeping firmware and app work aligned on access products.

• Offline-first behavior has already been proven in production, which is critical for locks and entry points that cannot rely on constant connectivity.

• Unlock and payment can be combined into a single flow, as shown by duration-based billing in TaskPod and multi-wallet checkout in Nakipower.

• Engagement models can fit both a first pilot and a multi-site rollout, including dedicated teams, staff augmentation, fixed-price, and time-and-materials.

Salt & Pepper: focused access and wearable builds

Salt & Pepper has worked on connected devices since 2016. The company holds a 4.9/5 rating on Clutch across 14 reviews and lists smart access control systems and wearable health devices in its portfolio.

Its teams are lean, usually 6 to 10 people, with React Native and Node.js as core technologies. Salt & Pepper has delivered app and cloud infrastructure for connected products, including Embr Wave, Tertill, and Vivor. Its work starts before development, with IoT consulting and proof-of-concept support, then continues through backend architecture, maintenance, and scaling.

Why choose Salt & Pepper:

• A senior, focused team fits mid-sized access and builds wearables better than a large, account-managed setup.

• Proof-of-concept support is useful when a lock, reader, or wearable integration needs validation before a full build is funded.

• End-to-end delivery covers discovery, design, development, maintenance, and scaling, so one vendor can stay with the product after launch.

Integra Sources: firmware and hardware from the ground up

Integra Sources works from PCB to application software. The company holds a 4.9/5 rating on Clutch across 26 reviews and received a Summer 2026 Clutch Global Award for IoT Development.

Founded in 2014, Integra Sources has grown to roughly 50 engineers and reports having completed 250+ projects, serving 100+ clients, and maintaining a 90% retention rate. Its stack includes C, C++, embedded Linux, BLE, Wi-Fi mesh, and CAN bus, with experience across aerospace, medical, and battery-management projects.

Delivery covers prototyping, testing, pre-certification, and documentation for electronics certification.

Why choose Integra Sources:

• Full hardware-to-software delivery suits devices where firmware is the hardest part.

• Deep embedded expertise fits access hardware with tight power, latency, and reliability requirements.

• Pre-certification support matters when a lock, reader, or connected device must pass compliance testing before mass production.

iomico: low-power wireless specialists

iomico has a 4.8/5 Clutch rating across 23 reviews and focuses on firmware-first connected-device work. Roughly 70% of its service mix sits in IoT and cyber-physical software.

Its stack covers Zephyr RTOS, BLE, LoRaWAN, Wi-Fi, RFID, NFC, and UWB, with MCU firmware across Nordic, Espressif, and Texas Instruments chips. In one engagement, the team reported a 60% reduction in power consumption and improved RFID scanning accuracy.

iomico also supports penetration testing and over-the-air update work, with engineers certified in OSCP, CISSP, and CCNA Cyber Ops.

Why choose iomico:

• Firmware optimization is critical for battery-powered locks, badges, and access devices.

• Strong experience with RFID, NFC, and UWB is a fit for contactless access hardware.

• In-house penetration testing provides teams with a security review process for devices that control physical entry.

Lemberg Solutions: certified engineering at scale

Founded in 2007 in Lviv, Lemberg Solutions has a team of 160+ engineers, architects, and data scientists. The company holds a 4.8/5 Clutch rating and ISO 9001, ISO 27001, and ISO 13485 certifications.

Its work spans embedded software, firmware, BLE, PCB design, and edge AI in a single workflow. Named clients include Bosch Rexroth. Delivered projects include energy-storage systems for Voltfang on an automotive-grade Infineon chip, EV charging station interfaces, and ASIL-D-compliant battery management.

Why choose Lemberg Solutions:

• Certified processes are suitable for connected products that control physical access or handle sensitive data.

• Hardware and firmware move through the same workflow, which shortens the feedback loop when a board revision affects app behavior.

• A larger engineering bench supports enterprise builds and long-running engagements.

SumatoSoft: platforms and integrations

SumatoSoft has delivered 350+ projects in 25+ countries since 2012 and holds a 4.8/5 rating on Clutch based on 25 reviews. The company is ISO 27001-certified and aligns its delivery with HIPAA and GDPR requirements.

About 70% of its engineers are senior-level. Its IoT practice focuses on custom platforms rather than standalone apps, with over-the-air update pipelines that include staged rollout, health checks, and automatic rollback. Named clients include Toyota, Beiersdorf, and the World Bank.

Why choose SumatoSoft:

• Custom IoT platforms fit access products that need more than a simple control app.

• OTA update pipelines help teams ship fixes safely after devices are in the field.

• Security and compliance experience is useful for products that handle sensitive user or operational data.

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Mercury Development: app-heavy and rescue work

Mercury Development was founded in 1999 and holds a 5.0/5 Clutch rating based on 33 reviews. Its Clutch profile lists more than 450 full-time staff.

The company builds mobile apps, IoT integrations, and cloud backends, with experience in connected-device software and product rescue. Its hardware-adjacent work includes Kensington Proximo, a line of BLE key fobs and tags with a companion app for tracking and locating them.

Clients include Google, HSBC, Fitbit, Tonal, and Dow. Apps built by the team have reached more than 40 million users.

Why choose Mercury Development:

• BLE key-fob and tag experience translates well to credential hardware and proximity unlock.

• Strong app and cloud-backend work fits access products where the mobile experience is central.

• Its product-assessment service helps teams stuck after a first vendor with a prioritized action plan before any rebuild starts.

Concepter: consumer smart hardware

Concepter was founded in 2013 in Kyiv and holds a 4.5 rating on Clutch. The studio combines product strategy, industrial and mechanical design, electrical engineering, and embedded work for consumer electronics.

It reports more than 20 shipped products and over 1 million product users, and has received recognition from the Red Dot Design Award and CES. Its portfolio includes JetBeep, a proximity hardware line for payments and loyalty, as well as Cardiomo and iBlazr 2.

Engagements start at a $1,000 minimum and can range from prototyping to mass-production consulting.

Why choose Concepter:

• Combined hardware and software design suits early-stage connected gadgets.

• Mass-production consulting helps with the stage where many first-time device founders get stuck.

• A low entry point makes it useful for paid discovery or prototyping before committing to a full build.

Questions to ask any IoT software development company before you sign

Every vendor will say yes to “Do you build IoT?” These questions help distinguish teams that can ship connected products from those that only build parts of them.

• Which parts of the stack do your own engineers write, and which do you subcontract? Ask about firmware, cloud, iOS, and Android separately. If a vendor subcontracts firmware, it introduces a handoff at the exact layer where lock-timing bugs often appear. Get the subcontractor’s name and confirm who holds that contract.

• Show a shipped product that works offline. How does it handle a dropped connection at the door? Ask what happens to a PIN issued while the device is offline and how the queue reconciles once the connection returns. A demo on a stable network answers a different question.

• How do you manage device provisioning, credentials, and revoked access across a fleet? Revocation is the part many teams skip. Ask how long a revoked credential keeps working on a device that has not checked in for a week.

• Which wireless protocols have your engineers shipped in production? BLE, NFC, UWB, LoRaWAN, and Wi-Fi mesh behave differently at range and under interference. For each protocol the vendor claims, ask for the product name and the year it shipped.

• How do you handle over-the-air updates, and what happens when one fails? Ask about staged rollout, health checks, and automatic rollback. A lock bricked by a bad update becomes a site visit, and that cost scales with every installed door.

• Who tests security, and against what? Ask whether penetration testing is done in-house or by a third party, then request the scope of the last report. A certification such as ISO 27001 shows that a process exists. The report shows what the team actually tested and found.

• What happens to source code and IP rights when the engagement ends? Put the answer in the contract. Cover repository ownership, build credentials, signing keys, and the firmware toolchain. Then ask what a handover to another vendor would actually involve.

Conclusion

Connected access is now as much a software problem as a hardware one. The vendor that can own the full chain is the one most likely to move a product past the pilot stage.

Axon fits this profile, with device-to-app ownership and offline entry already proven in production. Salt & Pepper, Integra Sources, and the other vendors each have a clear niche, from firmware-heavy work to app-led builds.

Match the partner to the part of the stack where your team needs the most support, and check offline behavior before anything else.