Sinacola Builds a Files.com Pass-Through to Retire Its Internet-Facing FTP Server

Sinacola is a heavy civil contractor headquartered in Frisco, Texas. The company is 100% employee-owned, with more than 700 employees and completed projects in over 100 cities across Texas, Arkansas, and Oklahoma: highways, airports, tollways, stadiums, mining operations, and large-scale data centers. It moves millions of cubic yards of earth a year.

Almost none of that work happens in an office. Sinacola's crews operate on dispersed job sites, carrying tablets and phones rather than workstations, and the company builds its own field applications in-house to run the work. The photos, survey data, and documents those crews capture are the office's record of what was found and done on site. All of it has to travel from the job site back to Sinacola's servers.

The Way In From the Field Started With an FTP Server

For years, the route in was an on-premises FTP server. Crews relayed photos and documents through it, and because crews are wherever the work is, the server had to be reachable from the internet. That meant a standing inbound opening through the corporate firewall, maintained for no other reason than to let files in.

IT wanted more from that path than plain FTP could give. When Sinacola scoped a replacement, the requirements described the gap exactly: SSH-secured transfer and two-factor authentication on every account, for a field workforce that connects from phones and tablets on job sites, not from desks behind the firewall.

“We want people to take pictures with cell phones and be able to upload them, and then we can turn off our FTP server.”

Cloud Storage Could Not Be the System of Record

The obvious fix was to point field uploads at a hosted file service and shut the old path down. Sinacola's IT directive ruled that out before it started. Cloud storage at Sinacola is reserved for non-critical data. Anything critical has to be recoverable on the company's own on-premises servers in a disaster. A project's field record is critical, so a cloud service could never be its only home.

That left a bind. Keeping the FTP server honored the directive but kept the exposure. Replacing it with cloud storage removed the exposure but violated the directive. The fix had to do three things at once: give field crews and field applications an easy, secured entry point in the cloud, hold that entry to IT's bar of SSH and two-factor authentication, and land everything on Sinacola's own servers automatically, so the cloud copy was never the copy that mattered.

Sinacola selected Files.com to be that layer: a cloud entry point for the field, with the landing on-prem.

A Pass-Through, Not a Destination

Files.com became a new route between the field and Sinacola's data center, rather than a place where data lives.

On the intake side, Sinacola's in-house Microsoft PowerApps applications write field data directly into Files.com, and crews upload job-site photos through the Files.com mobile app. System transfers run over SFTP, and two-factor authentication applies to accounts, which is the security bar the project was scoped against.

On the landing side, the Files.com Agent runs inside Sinacola's network and syncs everything that arrives in the cloud down to the company's on-premises servers. The Agent makes only outbound connections to Files.com, so Sinacola's destination servers do not have to listen to the internet for the sync to work. The design inverts the old arrangement: the internet-facing surface belongs to Files.com, while Sinacola's servers remain the system of record.

Thirty Photos in One Action, and Everything Lands On-Prem

With the pass-through in production, Sinacola's Files.com field-capture path runs from the phone to the data center. Photos and application data captured in the field land on Sinacola's on-premises servers with no one moving files by hand. The crew uploads, and the Files.com Agent brings everything home on its own.

Each field application the in-house team builds can write into the same Files.com pass-through, inheriting the same secured entry and on-premises landing without new infrastructure to stand up.

Bulk mobile upload is what made the path practical at field pace:

“Now they can just upload 30.”

Field Data Comes Home on IT's Terms

A crew member can select the day's photos on a phone and upload once. Files.com then delivers those files to Sinacola's own servers through a path that does not require an inbound opening into the company's network. Once field crews have adopted that mobile path, Sinacola can turn off its legacy FTP server and close the corresponding firewall opening.

Sinacola did not have to choose between securing its field perimeter and keeping its on-prem system of record. Files.com is the pass-through, not the destination, and that is exactly what made a cloud layer acceptable to an IT organization whose first rule is that critical data comes home.