Federal opportunities do not scatter across the internet the way sales leads do. They live in a short list of official systems, and knowing which one to check for which kind of buy saves you hours, either from missing real work or from watching a portal that was never going to show it to you.
SAM.gov: the one board you cannot skip
SAM.gov is the government's central, official system for contracting opportunities, and it costs nothing to use. Above the dollar thresholds that trigger public posting, agencies are required to announce their work here, across every department and most of what they buy. If you only ever check one place, make it this one. For most small businesses it is not just the starting point, it stays the main one.
GSA eBuy: for Schedule holders
eBuy carries requests for quotes and task orders issued under the GSA Multiple Award Schedule. It costs nothing to use, but most of what runs through it is visible only to companies that already hold a Schedule contract. If you are not on the Schedule, eBuy is not really for you yet. It becomes relevant the day you get on.
DIBBS: DLA's commodity board
DIBBS is the Defense Logistics Agency's system for buying commodities, spare parts, and supplies, the physical goods DLA moves in volume. It is free and narrow. If you do not sell into that lane, skip it entirely. If you do, check it directly rather than assuming SAM.gov alone surfaces everything DLA posts.
Agency-specific portals exist too
Beyond those three, individual agencies and components sometimes run their own supplemental listings, vendor outreach pages, or industry day announcements on top of what they post to SAM.gov. The portals themselves are not worth memorizing, but the pattern is: an agency that buys heavily in a niche tends to build a front door for that niche, in addition to its SAM.gov posting, not instead of it. If you sell mostly to one agency, spend a few minutes finding out whether it runs one. It is not worth keeping a bookmark folder for every portal every component has ever stood up.
What never posts anywhere
Purchases under the micro-purchase and simplified acquisition thresholds are often awarded without any public notice at all. A contracting officer can call a vendor they already know, or one they found through SBA's small business directory, and place the order directly. Nothing was hidden from you, and nothing was posted for anyone to see either. This is the real reason relationships and a filled-out DSBS profile matter as much as watching notices do. Some of this work is never announced. It is found.
The honest Quarry line
Quarry reads SAM.gov's public feed every night, the same feed anyone can read for free. We do not have a private pipe into opportunities you cannot see, and if we ever imply otherwise, write to support@quarrybids.com and we will fix the copy. What we spend hours on that you might rather not is reading everything that posts and only surfacing what actually fits your trade.